title: Cardiac assessment in pediatric mice: strain analysis as a diagnostic measurement.
abstract: Echocardiography is a robust tool for assessing cardiac function in both humans and laboratory animals. Conventional echocardiographic measurements, including chamber dimensions, wall thickness, and ejection fraction are routinely obtained to assess cardiac function in mice. Recently, myocardial strain and strain rate measurements have been added to functional assessments to provide additional details on regional abnormalities that are not evident using conventional measurements. To date, all studies of strain and strain rate in mice or rats have involved adult animals. This study serves to outline methods for acquiring echocardiographic images in pediatric mice and to provide myocardial strain and strain rate values for healthy C57BL/6J mice between 3 and 11 weeks old. Between weeks 3 and 11, left ventricular radial strain ranged from 32 to 43% and longitudinal strain ranged from -15 to -19%, with analysis over time showing no significant changes with aging (radial strain, P = 0.192 and longitudinal strain, P = 0.264; n = 4 for each time point evaluated). In conclusion, myocardial strain analysis in pediatric mice is technically feasible and has potential application in studying the pathophysiology of pediatric cardiovascular disease.
authors.affiliation: Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Andrews
authors.forename: Merry L
authors.initials: ML
authors.lastname: Lindsey
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lange
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Aune
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D015150:Echocardiography, Doppler / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009200:Myocardial Contraction / Q000502:physiology; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Pediatric; cardiac; echocardiography; left ventricle; myocardial strain; myocardial strain rate